Role Of Wnt/β-catenin Signaling Pathway In The Repair Of Intestinal Mucosa Associated With Crypt Stem Cell In A Rat Model Of Abdominal Compartment Syndrome

Objectives:The Wnt/β-catenin signaling plays a vital role in the maintenance of intestinal crypt epithelial cell regeneration,but its role in intestinal epithelial cell after injury is poorly understood.This study investigated the role of Wnt/β-catenin signaling on the regeneration of intestinal crypt stem cells in abdominal compartment syndrome(ACS)rat model.Methods:1.The establishment of ACS model:a rat model of abdominal compartment syndrome(ACS)was established by using a simple intra abdominal pressure gauge based on a Jiangsu Yuyue platform sphygmomanometer;2.Animal grouping and surgical treatment:48 male SD rats were randomly divided into sham group and ACS group(24 rats in each group).ACS group was induced by exposing to IAP under nitrogen pneumoperitoneum of 20 mm Hg for 0.5,2,4 or 6 hours,six SD rats per group;the rats in the sham operation group,of which only the operation process was performed,and no intra-abdominal pressure treatment was performed;the ACS group,of which the pressure measuring device was connected with the abdominal cavity in the left lower abdomen and injected with a certain amount of nitrogen,and the IAP was dynamically monitored and maintained until the scheduled time;3.Detection of content and methods:Each group was killed at the corresponding time and arterial blood was collected for biochemical analysis;then structural injury to the ileal mucosa at different hours of ACS was confirmed by light electron microscopy;moreover,the expression changes of Wnt/β-catenin signaling components Wnt-1,β-catenin,Transcription factor 4(TCF4)and c-Myc on mRNA and protein levels of the ileal mucosa were tested by Q-PCR and Western blot analyses;finally,immunofluorescence was used to detect the changes of β-catenin and c-Myc in the ileal mucosa.Results:1.Serum TP was 65.87 ±7.40 g/L,ALB was 28.9 ± 1.31 g/L,ALT was 78.3 ±8.85 U/L,AST was 256.17±9.56 U/L,UREA was 13.70± 1.34 mM,CREA was 24.43 ± 1.06 umol/L,CK was 742.63 ±51.35 U/L,a-HBDH was 366.37± 120.23 U/L in the sham group,while they of ACS group raised to 82.45 ±2.95 g/L(P<0.01),37.23 ± 0.46 g/L(P<0.01),659.2±26.56 U/L(P<0.01),948.47±67.72 U/L(P<0.01),20.30± 1.06 mM(P<0.01),43.76±4.13 umol/L(P<0,01),1948.01±90.66 U/L(P<0.01),747.27±38.24 U/L(P<0.01)after 20 mmHg IAP for 6 hours;2.Microscopic observation showed that there was no obvious damage to the ileal mucosa in the sham operation group,which showed that the normal columnar epithelium was optical;however,in the ACS group,extensive ileal villus damage was exposed to prolonged intra-abdominal pressure;3.Moreover,ACS injury was shown the mRNA and protein expressions for Wnt-1,β-catenin,TCF4,and c-Myc,which performances were increased first and then reduced;4.Immunofluorescence staining confirmed the expressions of proteins of β-catenin and c-Myc in the intestinal crypt stem cells according to morphology.Conclusions:1.Liver,kidney,heart and other organs were injured after ACS indicated by the blood biochemical analysis,and ACS causes the intestinal mucosal injury,which aggravates with time;2.and the Wnt/β-catenin signaling pathway is involved in intestinal epithelium regeneration,which is associated with crypt stem cells in early stage after ACS injury,but this effect was gradually suppressed over time;3.This study is the first time to demonstrate the expression of β-catenin after ACS intestinal injury.